Fish swim by and a sponge grows among amphora from a 4th century B.C. Greek merchant ship found in 200 feet of water off Chios in the Aegean Sea and photographed by SeaBED. (?Chios 2005 Shipwreck Survey: -Woods Hole Oceanographic Institution; Hellenic Ministry of Culture, Ephorate of Underwater Antiquities; and Hellenic Center for Marine Research)

Neil McPhee (left) and Hanumant Singh of WHOI monitor the launch of SeaBED, an autonomous underwater vehicle (AUV), from the research vessel Aegaeo off the island of Chios, Greece. The vehicle took more than 7,500 images on four dives to the shipwreck. (Photo by Brian Bingham, Franklin W. Olin College of Engineering)

Robots can do in days what humans take years to accomplish at archaeological sites

After lying hidden for millennia off the coast of Greece, a sunken 4th
century B.C. merchant ship and its cargo have been surveyed by an international team using a
robotic underwater vehicle. The group accomplished in two days what it would
take divers years to do. The project, the first in a new
collaboration between U.S. and Greek researchers, demonstrates the
potential of new technology and imaging capabilities to rapidly advance
marine archaeology.

Greek scientists and archaeologists discovered the ancient
shipwreck in 2004 during a sonar survey. The wooden Greek merchant ship
sank between Chios and Oinoussia islands in
the eastern Aegean Sea in 60 meters (about 200 feet) of water, too deep
for conventional SCUBA diving. The
most visible remains of the shipwreck are its cargo of 400 ceramic
jars, called amphoras. Team archaeologists believe the amphoras
probably contained wine and olive
oil.

Forgotten for more than two thousand years, the ship might never have revealed
its clues to ancient Greek culture until a research team from the Woods
Hole Oceanographic Institution (WHOI), Massachusetts Institute of
Technology (MIT), the Greek Ministry of Culture, and the Hellenic
Centre for Marine Research (HCMR) joined forces. Using a novel
autonomous underwater vehicle (AUV) named SeaBED developed and operated
by WHOI, the team made a high-precision photometric survey of the site
using techniques developed by WHOI and MIT researchers over the
past eight years.

Hanumant Singh and team at
the WHOI Deep Submergence Laboratory (DSL) designed and built SeaBED. DSL has been a leader in
developing and building submersible robotic vehicles for a variety of underwater environments,
including the towed ARGO vehicle that found the wrecks of Titanic and
Bismarck and the JASON II remotely operated vehicle that explores the
seafloor today.

The Chios wreck survey demonstrates how advanced technology can dramatically
change the field of underwater archeology, said WHOI deepwater archaeologist Brendan Foley.

For a single three-hour dive, SeaBED was programmed to “fly” over
the
shipwreck site in precisely spaced tracks. Multibeam sonar completely
mapped the wreck while a digital camera collected thousands of
high-resolution images. The vehicle took 7,650 images on four dives to
reveal the ship's ceramic cargo and marine life, including bright
yellow sponges and colorful fish. The vehicle never touched the wreck,
leaving it in an undisturbed state, important for future studies.

Robotic technology is the only way to reach deep shipwrecks like the
one at Chios, but the systems can also be applied to shallower sites.

Most human diving time on archaeological sites is consumed with basic
mapping tasks. Typically it takes hundreds of diving hours over several years to make a
site plan using tape measures and clipboards. The new robotic techniques produce results very quickly. Robotic vehicles can map
and create a photomosaic of a site with quantifiable accuracy in as
little as a few hours.

As soon as
SeaBED brought the first images from the Chios wreck to the surface,
project archaeologists began interpreting the data. The images were assembled into mosaics that depict minute features of the
shipwreck with unmatched clarity and detail.

“By using this technology, diving archeologists will be freed from
routine measuring and sketching tasks, and instead can concentrate on
the things people do better than robots: excavation and data
interpretation,” contends Singh, an engineering and imaging scientist.
“With repeated performances, we'll be able to survey shipwrecks faster
and with greater accuracy than ever before.”

The historic value in ships,such as the Chios wreck is
the information they provide about ancient trade networks. The wreck is
“like a buried UPS truck,” said David Mindell, a professor of
engineering history and systems
at MIT. “It provides a wealth of information that helps us figure out
networks based on the contents of the truck.”

The island of Chios was famous throughout the Classical Greek world for
its wine. Athens was its largest customer, but Chios sold its products
in markets as far flung as the Crimea and Cyprus. Foley said the wreck's cargo is the largest
assemblage of Chian amphoras found to date, and provides valuable data
about the volume of ancient trade. The team's 2005 survey showed that despite the turmoil of the Peloponnesian War and
subsequent break-up of the Athenian empire, Chios was still engaged in
trade in the 4th century B.C.

“Our technologies allow us to learn about the past in ways that we
couldn’t achieve otherwise,” Foley said. “We’re not looking for footnotes any more. We’re looking to
write new chapters, and are convinced that in 10 to 15 years using
these methods, we will have changed history.”

The team's research program is scheduled to last ten years or more and is
focused on uncovering sites dating to the dawn of civilization in the
Mediterranean: the Bronze Age (2500 to 1200 B.C.), and Minoan and
Mycenaean cultures and their trading
partners.

“We’re looking forward to continuing the project next summer,” HCMR geologist Dimitris
Sakellariou said. “We will be exploring many more sites using new
chemical sensors to collect environmental data about the shipwrecks,
something that has not been done before. It is a very exciting
collaboration. ”

In addition to Foley, Singh, and Mindell, the American team for the
Chios expedition included Brian Bingham of Franklin W. Olin College of
Engineering; Richard Camilli, Ryan Eustice, and Chris Roman from WHOI;
and David C. Switzer of Plymouth State University. HCMR geologist
Dimitris Sakellariou led the Greek science and technical team, while
Katerina Delaporta, Director of the Ministry of Culture’s Ephorate of
Underwater Antiquities, headed the Greek archaeology team.

The team presented preliminary results at the November 2005 American Schools of Oriental Research conference in Philadelphia.